JP2006334649A - Die casting apparatus and die casting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die casting apparatus which can reconcile the improvement of the quality of a molding and operability. <P>SOLUTION: The die casting apparatus 1 is equipped with: a die 2 composed of a fixed die 3 and a movable die 4 in which a cavity 11 is formed at a mating face; an unloading member 6 which is provided with extrusion pins 61a, 61b stored into storing holes penetrating from the cavity face 41b of the cavity into the back face 42b of the movable die, a moving plate 62 in which bases of the extrusion pins are fixed to one side, and sliding pins 63a, 63b fixed to the other side of the moving plate, and which peels a molding stuck to the cavity and unloading the same; a chamber forming member 7 of forming a chamber 12 storing the moving plate movably in the sliding direction of the extrusion pins and communicating with the storing holes, and further supporting halfway parts of the sliding pins in the unloading member so as to be slidable; and a cavity pressurizing/depressurizing device 8 and a chamber pressurizing/depressurizing device 9 for pressurizing and depressurizing the cavity and the chamber. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal or resin die casting apparatus and a die casting method.

Conventionally, metal or resin die casting apparatuses and die casting methods are known.
A conventional die casting apparatus generally supplies a mold having a fixed mold and a movable mold each having a cavity formed on a mating surface, and supplies molten metal or resin (hereinafter referred to as “molten metal”) to the cavity. The injection device is provided, and the molten metal is solidified in the cavity to be molded into a molded product having a predetermined shape.
There is also known a die casting apparatus including a decompression pump that depressurizes the cavity in order to prevent bubbles from being involved in the molded product and improve the quality of the molded product.
Furthermore, when the material of the fixed mold and the movable mold is mold steel, and the molten metal is an aluminum alloy, the molten metal supplied to the cavity has a cavity surface (the outer shape of the cavity) of the fixed mold and the movable mold. If it is easy to adhere to the cavity surface, a release agent is applied to the cavity surface, and an extrusion pin that protrudes into the cavity of the stationary mold and the movable mold is provided, and adheres to the cavity surface of the stationary mold and the movable mold. There is also known a die casting apparatus that peels off the molded product.

  A die casting apparatus having the above-mentioned extrusion pin usually penetrates from the cavity surface of the fixed mold and the movable mold to the back surface (the surface opposite to the mating surface in the fixed mold and the movable mold), and slides the extrusion pin. A hole is formed to be movably accommodated, and includes an actuator (such as a hydraulic cylinder) for sliding the push pin in a direction protruding into the cavity and a direction retracting from the cavity.

  Also, in the fixed mold and movable mold, if the peripheral part of the cavity is a separate member from the main mold and can be attached to and detached from the main mold, it is inevitably necessary to consider the insert in consideration of workability at the time of attachment / detachment A gap is formed between the main mold.

It is excellent from the viewpoints of improving the workability of the die casting apparatus and maintaining equipment costs to provide the above-mentioned extrusion pin and to make the fixed mold and the movable mold as separate members of the nest and the main mold forming the periphery of the cavity.
However, the hole or nesting between the dies and the main mold that slidably accommodates the extrusion pin provided in the mold described above causes a deterioration in the quality of the molded product due to a decrease in the degree of vacuum when the cavity is depressurized (the occurrence of cast holes). Etc.) and a long time required to reach a predetermined degree of vacuum becomes a factor of a decrease in productivity.

Therefore, as a die casting apparatus that solves the above problem, a hole that slidably accommodates the extrusion pin provided in the mold or a chamber that is a separate space communicating with the gap between the insert and the main mold is provided inside the mold. Another vacuum pump that efficiently depressurizes the gap between the hole and the insert and the main mold that is formed and connected to the chamber and depressurizes the chamber to slidably accommodate the extrusion pin provided in the mold. There is known a die casting apparatus comprising: For example, as described in Patent Document 1.
JP 2001-71106 A

However, the die casting apparatus described in Patent Document 1 has the following problems.
First, since the die casting apparatus described in Patent Document 1 is configured to form a chamber inside the mold by intentionally widening a part of the gap between the insert and the main mold, the mold is closed. In some cases, the nesting and the main mold are deformed in such a manner that the chamber is crushed when the cavity is decompressed, and the dimensional accuracy of the molded product may be lowered. In addition, there is a case where a gap between the insert and the main mold becomes large due to deformation of the insert and the main mold, and a part of the molten metal supplied to the cavity is inserted into the gap to generate burrs.
Secondly, in the die casting apparatus described in Patent Document 1, an extrusion pin penetrates the chamber and protrudes to the back surface of the fixed type and the movable type, and an O-ring or the like is provided in the middle of the hole accommodating the extrusion pin. A seal member is provided, and the seal member and the push pin are in sliding contact with each other in an airtight manner, so that the seal member is easily damaged and airtight. In order to ensure, work such as frequent replacement of the seal member is necessary, and maintenance is not good.

  In view of the circumstances as described above, the present invention prevents the deformation of the mold when the cavity is decompressed and the seal member is damaged in order to ensure the hermeticity of the chamber even in the configuration having the extrusion pin and the chamber. Therefore, it is an object of the present invention to provide a die casting apparatus that can improve both the quality of a molded product and workability.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

That is, in claim 1,
A mold composed of a fixed mold and a movable mold in which a cavity surface forming the outer shape of the cavity is formed on the mating surface;
Extrusion pin slidably accommodated in an accommodation hole penetrating from the cavity surface to the back surface of one or both of the fixed mold and the movable mold, and a movable plate having a base portion of the extrusion pin fixed to one surface And a slide pin fixed to the other surface of the moving plate, and a takeout member for peeling off and taking out the molded product attached to the cavity surface;
A moving plate of the take-out member is accommodated so as to be movable in the sliding direction of the push pin, and a chamber communicating with the accommodation hole is formed facing the back surface of either the fixed mold or the movable mold. A chamber forming member that slidably supports a middle portion of the sliding pin of the takeout member;
A cavity pressure increasing / decreasing device for pressurizing and depressurizing the cavity;
A chamber pressurizing and depressurizing device for pressurizing and depressurizing the chamber;
It comprises.

In claim 2,
The take-out member is
The movable plate includes a substantially ring-shaped seal member that is in contact with the surface on which the sliding pin is fixed and the inner wall surface of the chamber and is fitted onto the sliding pin.

In claim 3,
The fixed mold comprises a fixed-side insert in which a cavity surface that forms the outer shape of the cavity is formed, and a fixed-side main mold that removably fixes the fixed-side insert.
The movable mold includes a movable nest having a cavity surface that forms the outer shape of the cavity, and a movable main mold for detachably fixing the movable nest.

In claim 4,
A mold composed of a fixed mold and a movable mold in which a cavity surface forming the outer shape of the cavity is formed on the mating surface;
Extrusion pin slidably accommodated in an accommodation hole penetrating from the cavity surface to the back surface of one or both of the fixed mold and the movable mold, and a movable plate having a base portion of the extrusion pin fixed to one surface And a slide pin fixed to the other surface of the moving plate, and a takeout member for peeling off and taking out the molded product attached to the cavity surface;
A moving plate of the take-out member is accommodated so as to be movable in the sliding direction of the push pin, and a chamber communicating with the accommodation hole is formed facing the back surface of either the fixed mold or the movable mold. A chamber forming member that slidably supports a middle portion of the sliding pin of the takeout member;
A cavity pressure increasing / decreasing device for pressurizing and depressurizing the cavity;
A chamber pressurizing and depressurizing device for pressurizing and depressurizing the chamber;
A die casting method using a die casting apparatus comprising:
A depressurizing step of closing the mold and depressurizing the cavity and the chamber;
A molding step of supplying a molten metal to the cavity and solidifying the molten metal to mold a molded product;
Pressurizing the cavity and the chamber above atmospheric pressure to open the mold, protruding the extrusion pin into the cavity, and removing the molded article from the mold;
It comprises.

In claim 5,
Before the decompression step,
A release agent coating step is provided in which a release agent is applied to a cavity surface formed on a mating surface of the fixed mold and the movable mold in a state where the chamber is pressurized to atmospheric pressure or higher.

In claim 6,
The molded product takeout member is:
The movable plate includes a substantially ring-shaped seal member that is in contact with the surface on which the sliding pin is fixed and the inner wall surface of the chamber and is fitted onto the sliding pin.

In claim 7,
The fixed mold comprises a fixed-side insert in which a cavity surface that forms the outer shape of the cavity is formed, and a fixed-side main mold that removably fixes the fixed-side insert.
The movable mold includes a movable nest having a cavity surface that forms the outer shape of the cavity, and a movable main mold for detachably fixing the movable nest.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, air entrainment is prevented, dimensional accuracy is ensured, and generation of burrs is prevented, thereby contributing to improvement of the quality of the molded product. Further, the molded product can be easily taken out from the mold, and the workability is excellent.

  In claim 2, it is possible to prevent damage to the seal member.

  In Claim 3, it is possible to replace only the fixed side insert and the movable side insert, thereby reducing the equipment maintenance cost.

  According to the fourth aspect of the present invention, air entrainment is prevented, dimensional accuracy is ensured, and occurrence of burrs is prevented, thereby contributing to improvement in the quality of the molded product. Further, the molded product can be easily taken out from the mold, and the workability is excellent.

According to the fifth aspect, the molded product is prevented from firmly adhering to the cavity surface, and the molded product can be easily taken out.
In addition, by preventing the release agent from entering and remaining in the accommodation hole, it is possible to prevent a decrease in the degree of vacuum at the time of decompression of the cavity caused by the remaining release agent, thereby contributing to the improvement of the quality of the molded product. .

  According to the sixth aspect of the present invention, it is possible to prevent damage to the seal member.

  According to the seventh aspect of the present invention, it is possible to replace only the fixed side insert and the movable side insert so as to reduce the equipment maintenance cost.

  Below, the structure of the die-casting apparatus 1 which is one Embodiment of the die-casting apparatus based on this invention is demonstrated using FIG. 1 and FIG.

The die casting apparatus 1 is an apparatus for solidifying a molten metal made of an aluminum alloy to form a molded product having a predetermined shape.
The die casting apparatus 1 of the present embodiment is an apparatus for solidifying a molten metal made of an aluminum alloy and forming it into a molded product having a predetermined shape. However, the present invention uses various metals and various resins in a molten state. The present invention can be widely applied to uses that are solidified and molded into a molded product having a predetermined shape.

  The die casting apparatus 1 mainly includes a mold 2, an injection apparatus 5, a takeout member 6, a chamber forming member 7, a cavity pressure increasing / decreasing apparatus 8, a chamber pressure increasing / decreasing apparatus 9 and the like.

  The mold 2 is an embodiment of the mold according to the present invention, and mainly includes two members, a fixed mold 3 and a movable mold 4.

  The fixed mold 3 is an embodiment of the fixed mold according to the present invention, and is a member fixed at a predetermined position among the two members constituting the mold 2. The fixed mold 3 includes a fixed side insert 31, a fixed side main mold 32, and the like.

  The fixed-side insert 31 is an embodiment of the fixed-side insert according to the present invention, and is a member that forms a portion that actually contacts the molten metal in the fixed mold 3. A cavity surface 31 b is formed on the mating surface 31 a of the fixed side insert 31.

  The fixed-side main mold 32 is an embodiment of the fixed-side main mold according to the present invention, and is a main structure that fixes the fixed-side insert 31 detachably and secures the strength of the fixed mold 3 (prevents deformation). It is the member which comprises.

In a state where the fixed side nest 31 is fixed to the fixed side main mold 32, the mating surface 32a of the fixed side main mold 32 and the mating surface 31a of the fixed side nest 31 form substantially the same plane.
By making the fixed side insert 31 and the fixed side main mold 32 constituting the fixed mold 3 as separate bodies as in this embodiment, the cavity surface 31b of the fixed side insert 31 is damaged by contact with the molten metal and has a predetermined dimension. Even when the accuracy is no longer satisfied, it is possible to restore the fixed mold 3 to the original state (the state where the cavity surface 31b satisfies the predetermined dimensional accuracy) by replacing only the fixed side insert 31. Therefore, it is possible to reduce the equipment maintenance cost of the die casting apparatus 1 as compared with the case where the fixed side insert 31 and the fixed side main mold 32 are integrated.

  A gap 33 is formed between the fixed-side main mold 32 and the fixed-side insert 31 in consideration of workability during attachment / detachment. The gap 33 communicates with the back surface 32b (the surface on the opposite side of the mating surface 32a) of the fixed-side main mold 32.

An exhaust path 31 c is formed in the fixed side insert 31, and an exhaust path 32 c is formed in the fixed side main mold 32. One end of the exhaust path 31 c communicates with the cavity surface 31 b, and the other end communicates with the upper surface of the fixed side insert 31.
One end of the exhaust path 32 c communicates with the exhaust path 31 c and the other end communicates with the upper surface of the stationary main mold 32.
An exhaust valve 34 is provided in the middle of the exhaust path 32c. The exhaust valve 34 is operated by compressed air supplied by an air supply means (not shown), and a state where the middle part of the exhaust path 32c is closed (closed state) and a state where the middle part of the exhaust path 32c is not blocked (open state). ) And can be switched.

  The movable mold 4 is an embodiment of the movable mold according to the present invention, and is a member that moves relative to the fixed mold 3 among the two members that constitute the mold 2. The movable mold 4 includes a movable-side insert 41, a movable-side main mold 42, and the like.

  The movable-side insert 41 is an embodiment of the movable-side insert according to the present invention, and is a member that forms a part of the movable mold 4 that actually contacts the molten metal. A cavity surface 41 b is formed on the mating surface 41 a of the movable side insert 41.

  The movable-side main mold 42 is an embodiment of the movable-side main mold according to the present invention, and is a main structure that fixes the movable-side insert 41 detachably and ensures the strength of the movable mold 4 (prevents deformation). It is the member which comprises.

In a state where the movable side nest 41 is fixed to the movable side main mold 42, the mating surface 42a of the movable side main mold 42 and the mating surface 41a of the movable side nest 41 form substantially the same plane.
By making the movable side insert 41 and the movable side main mold 42 constituting the movable mold 4 separate as in this embodiment, the cavity surface 41b of the movable side insert 41 is damaged by contact with the molten metal and has a predetermined dimension. Even when the accuracy is not satisfied, it is possible to restore the movable mold 4 to the original state (the state where the cavity surface 41b satisfies the predetermined dimensional accuracy) by replacing only the movable side insert 41. Therefore, the equipment maintenance cost of the die casting apparatus 1 can be reduced as compared with the case where the movable side insert 41 and the movable side main mold 42 are integrated.

As shown in FIG. 1, the mold 2 is closed, that is, the mating surface 31 a of the fixed side insert 31 constituting the fixed die 3 and the mating surface 32 a of the fixed side main die 32 and the movable side insert 41 constituting the movable die 4. In a state where the mating surface 41a and the mating surface 42a of the movable main mold 42 are in contact with each other, a cavity 11 that is a space having a predetermined shape is formed inside the mold 2. The cavity surface 31b and the cavity surface 41b form the outer shape of the cavity 11, and correspond to the shape of the molded product.
An O-ring 44 is provided on the mating surface 42 a of the movable main mold 42 to ensure the airtightness of the cavity 11.

A gap 43 is formed between the movable side main mold 42 and the movable side insert 41 in consideration of workability at the time of attachment / detachment.
Also, the movable side insert 41 and the movable side main mold 42 are formed with receiving holes 41c and 42c and receiving holes 41d and 42d penetrating from the cavity surface 41b to the back surface 42b of the movable side main mold 42. The accommodation holes 41 c and 42 c and the accommodation holes 41 d and 42 d communicate with the gap 43.

  The injection device 5 supplies molten metal to the cavity 11 of the mold 2 and mainly includes an injection sleeve 51, a plunger tip 52, an injection cylinder 53, and the like.

The injection sleeve 51 is a substantially cylindrical member, and one end of the injection sleeve 51 projects from the lower part of the back surface 32 b of the fixed-side main mold 32. One end of the injection sleeve 51 communicates with a molten metal supply path 32 d formed in the stationary main mold 32.
Further, the molten metal supply path 32 d communicates with the molten metal supply path 31 d formed in the stationary side insert 31, and the molten metal supply path 31 d communicates with the cavity 11.
A molten metal supply port 51 a is formed in the middle of the injection sleeve 51, and the molten metal is poured into the injection sleeve 51 from the molten metal supply port 51 a.

  The plunger tip 52 is a substantially cylindrical member that is in fluid-tight sliding contact with the inner peripheral surface of the injection sleeve 51.

  The injection cylinder 53 is a hydraulic cylinder for sliding the plunger tip 52 along the inner peripheral surface of the injection sleeve 51.

The take-out member 6 is an embodiment of the take-out member according to the present invention, and is for peeling and removing the molded product attached to the cavity surface 41 b of the cavity 11.
The take-out member 6 mainly includes push-out pins 61a and 61b, a moving plate 62, slide pins 63a and 63b, O-rings 64a and 64b, and the like.

The extrusion pins 61a and 61b are an embodiment of the extrusion pin according to the present invention.
The extrusion pins 61a and 61b are substantially cylindrical members, and are slidably accommodated in the accommodation holes 41c and 42c and the accommodation holes 41d and 42d, respectively. The tip portions of the extrusion pins 61 a and 61 b face the cavity 11, and the base portions of the extrusion pins 61 a and 61 b protrude from the back surface 42 b of the movable main mold 42.

The moving plate 62 is an embodiment of the moving plate according to the present invention.
The moving plate 62 is a plate-like member, and the bases of the push-out pins 61a and 61b are fixed to one surface thereof.

The sliding pins 63a and 63b are an embodiment of the sliding pin according to the present invention.
The sliding pins 63a and 63b are substantially cylindrical members, and one end thereof is fixed to the other surface of the moving plate 62 (the surface opposite to the surface to which the bases of the push-out pins 61a and 61b are fixed).

The O-rings 64a and 64b are an embodiment of the sealing member according to the present invention.
The O-rings 64a and 64b are substantially ring-shaped members made of silicone rubber, and are fitted on the sliding pins 63a and 63b, respectively. Further, the O-rings 64a and 64b are fixed in a state where the O-rings 64a and 64b are in contact with the surface on which the sliding pins 63a and 63b are fixed.

In this embodiment, the number of extrusion pins fixed to the moving plate is two, but the state of adhesion of the molded product to the mold also changes due to changes in the size and shape of the cavity, the material of the mold and the molded product, etc. Therefore, it is desirable to appropriately change the number and the arrangement thereof according to these.
Similarly, in this embodiment, the take-out member is arranged only on the movable mold side, but according to the state of adhesion of the molded product to the mold, it can be arranged only on the fixed mold side, or the movable mold side and It is also possible to adopt a configuration in which take-out members are arranged on both of the fixed mold side.

The chamber forming member 7 is an embodiment of the chamber forming member according to the present invention.
The chamber forming member 7 is attached to the back surface 42 b of the movable side main mold 42. A recess is formed in a surface of the chamber forming member 7 that faces the back surface 42b of the movable main mold 42, and a chamber 12 that is a space surrounded by the recess and the back surface 42b of the movable main mold 42 is formed. The That is, the chamber forming member 7 faces the back surface 42 b of the movable main mold 42 and forms the chamber 12.

The chamber 12 accommodates the movable plate 62 so as to be movable in the sliding direction of the push pins 61a and 61b, that is, in the longitudinal direction of the accommodation holes 41c and 42c and the accommodation holes 41d and 42d.
The chamber 12 communicates with the accommodation holes 41c and 42c and the accommodation holes 41d and 42d, and communicates with the outside through the connection path 71.

  Support holes 72a and 72b penetrating from the chamber 12 to the outside are formed in the chamber forming member 7, and sliding pins 63a and 63b are inserted therethrough. Therefore, the chamber forming member 7 supports the middle portions of the slide pins 63a and 63b of the takeout member 6 so as to be slidable.

As shown in FIG. 1, when the take-out member 6 is in the retracted position, that is, when the push-out pins 61 a and 61 b do not protrude into the cavity 11, the O-rings 64 a and 64 b abut against the inner wall surface 73 of the chamber 12. 12 and the support holes 72a and 72b are blocked, and the airtightness of the chamber 12 is secured.
In this embodiment, the material of the O-ring is silicone rubber, but other materials may be used as long as the airtightness between the chamber and the outside can be secured.

  As shown by a two-dot chain line in FIG. 2, when the takeout member 6 is in the takeout position, that is, when the push pins 61 a and 61 b protrude into the cavity 11, the O-rings 64 a and 64 b are separated from the inner wall surface 73 of the chamber 12. Separate.

The cavity pressure increasing / decreasing device 8 is an embodiment of the cavity pressure increasing / decreasing device according to the present invention.
The cavity pressurizing and depressurizing device 8 pressurizes and depressurizes the cavity 11, and mainly includes a pressurizing pump 81, a depressurizing pump 82, a switching valve 83, pipes 84, 85, 86, and 87.
The pressurizing pump 81 is a pump for pressurizing the cavity 11. The exhaust port of the pressure pump 81 is connected to one end of the pipe 85.
The decompression pump 82 is a pump for decompressing the cavity 11. The intake port of the decompression pump 82 is connected to one end of the pipe 86.
The switching valve 83 is a valve for switching between pressurization and decompression of the cavity 11.
The switching valve 83 is connected to the other end of the pipe 85, the other end of the pipe 86, and one end of the pipe 84. The other end of the pipe 84 is connected to the exhaust path 32c.
In the switching valve 83, (1) the pipe 84 and the pipe 85 are communicated and the pipe 86 is closed (when pressurized), or (2) the pipe 84 and the pipe 86 are communicated and the pipe 85 is blocked. It is possible to switch to any of the states (during decompression).
In the case of the present embodiment, one end of the pipe 87 is connected to the middle part of the pipe 84 and the other end is connected to the gap 33. Therefore, the gap 33 can be pressurized and depressurized.

The chamber pressure increasing / decreasing device 9 is an embodiment of the chamber pressure increasing / decreasing device according to the present invention.
The chamber pressurizing / depressurizing device 9 pressurizes and depressurizes the chamber 12, and mainly includes a pressurizing pump 91, a depressurizing pump 92, a switching valve 93, pipes 94, 95, and 96.
The pressurizing pump 91 is a pump for pressurizing the chamber 12. The exhaust port of the pressure pump 91 is connected to one end of the pipe 95.
The decompression pump 92 is a pump for decompressing the chamber 12. The intake port of the decompression pump 92 is connected to one end of the pipe 96.
The switching valve 93 is a valve for switching between pressurization and decompression of the chamber 12.
The switching valve 93 is connected to the other end of the pipe 95, the other end of the pipe 96, and one end of the pipe 94. The other end of the pipe 94 is connected to the connection path 71.
In the switching valve 93, (1) the pipe 94 and the pipe 95 communicate with each other and the pipe 96 is closed (when pressurized) or (2) the pipe 94 and the pipe 96 communicate with each other and the pipe 95 is blocked. It is possible to switch to any of the states (during decompression).

Hereinafter, an embodiment of the die casting method according to the present invention will be described with reference to FIG.
As shown in FIG. 3, one embodiment of the die casting method according to the present invention is a die casting method using the die casting apparatus 1, which mainly includes a release agent coating process 100, a decompression process 200, a molding process 300, and a molded product take-out process. 400 and the like.

The release agent coating step 100 is performed by combining the fixed mold 3 and the movable mold 3 with the chamber 12 (and thus the gap 43, the accommodation holes 41c and 42c and the accommodation holes 41d and 42d) and the gap 33 being pressurized to atmospheric pressure or higher. This is a step of applying a mold release agent to the cavity surfaces 31b and 41b formed in the above.
Here, the “release agent” in the present application is applied to the cavity surface in order to prevent the molded product from firmly adhering to the cavity surface, and in this embodiment, a mixture of sulfate and water. Is used. In addition, the mold release agent which concerns on this invention is not limited to a present Example.

In the release agent application step 100, the switching valve 83 is switched to “the piping 84 and the piping 85 are in communication and the piping 86 is closed”, and the switching valve 93 is switched to “the piping 94 and the piping 95 are in communication and piping. 96 is closed ”.
As a result, the air pumped from the pressurizing pump 81 blows out from the gap 33 to the mating surface of the fixed mold 3, and the air pumped from the pressurizing pump 91 passes through the chamber 12 and the gap 43, the receiving holes 41 c and 42 c and the storing. Blow out from the holes 41d and 42d to the mating surface of the movable mold 4.

Next, a release agent is sprayed and applied to the cavity surfaces 31b and 41b with a spray gun or the like. At this time, air is blown out from the gap 33, the gap 43, the accommodation holes 41c and 42c and the accommodation holes 41d and 42d to the mating surfaces of the fixed mold 3 and the movable mold 4, respectively. There is no intrusion into the accommodation holes 41c and 42c and the accommodation holes 41d and 42d.
Therefore, the mold release agent adheres to the gap 33, the gap 43, the accommodation holes 41c and 42c, and the accommodation holes 41d and 42d to obstruct the movement of the extrusion pins 61a and 61b, or is caused by the release agent in the decompression step 200 described later. Thus, it is possible to prevent the vacuum degree of the cavity 11 from being lowered (for example, when water vapor or other gas components are generated from the release agent).
When the release agent coating process 100 is completed, the process proceeds to the decompression process 200.

The decompression process 200 is a process of decompressing the cavity 11 and the chamber 12 by closing the mold 2.
In the decompression step 200, first, the mold 2 is closed. At this time, the take-out member 6 is fixed at the retracted position (position shown in FIG. 1) by a locking member (not shown).

Next, the exhaust valve 34 is opened, and the switching valve 83 is switched to “a state where the pipe 84 and the pipe 86 communicate with each other and the pipe 85 is closed”, and the switching valve 93 is switched to “the pipe 94 and the pipe 96 communicate with each other. The state is switched to “the state in which the pipe 95 is closed”.
As a result, the air in the cavity 11 and the gap 33 is exhausted to the outside by the decompression pump 82, and the air in the gap 43, the accommodation holes 41 c and 42 c and the accommodation holes 41 d and 42 d is exhausted to the outside through the chamber 12 by the decompression pump 92. Is done.
When the cavity 11 is depressurized to a predetermined pressure, the depressurization step 200 is finished and the process proceeds to the molding step 300.

The molding process 300 is a process of supplying a molten metal to the cavity 11 and solidifying the molten metal to mold a molded product.
In the molding process 300, the molten metal is poured into the injection sleeve 51 from the molten metal supply port 51 a in a state where the plunger chip 52 is located behind the molten metal supply port 51 a (away from the mold 2). Is moved forward (toward the mold 2).
As a result, the molten metal is supplied to the cavity 11 through the molten metal supply path 32d and the molten metal supply path 31d. And the state as it is for a predetermined time is hold | maintained until a molten metal solidifies.

In the molding step 300, the air in the cavity 11 and the gap 33 is exhausted to the outside by the decompression pump 82 following the decompression step 200, and the air in the gap 43, the accommodation holes 41 c and 42 c and the accommodation holes 41 d and 42 d is exhausted by the decompression pump 92. The air is exhausted outside through the chamber 12.
Therefore, air is not supplied to the cavity 11 from the gap 33, the gap 43, the accommodation holes 41c and 42c, and the accommodation holes 41d and 42d, and the degree of vacuum of the cavity 11 can be kept high. As a result, it is possible to prevent air from getting into the molded product and improve the quality of the molded product.
When the molten metal is solidified (when the molded product is molded), the molding process 300 is finished, and the process proceeds to the molded product take-out process 400.

In the molded product removal step 400, the cavity 11 and the chamber 12 are pressurized to atmospheric pressure or higher to open the mold 2, and the extrusion pins 61a and 61b protrude into the cavity 11 to be removed by peeling the molded product from the mold 2. It is.
In the molded product removal step 400, the exhaust valve 34 is opened, the switching valve 83 is switched to “the piping 84 and the piping 85 are in communication and the piping 86 is closed”, and the switching valve 93 is switched to “the piping 94”. Switching to the state where the pipe 95 communicates and the pipe 96 is closed.
As a result, the air pumped from the pressurizing pump 81 is supplied to the cavity 11 through the exhaust passages 32c and 31c, and the cavity 11 is pressurized to atmospheric pressure or higher.
In addition, a part of the air pumped from the pressurizing pump 81 is supplied to the gap 33, and the air pumped from the pressurizing pump 91 passes through the chamber 12 and the gap 43, the receiving holes 41 c and 42 c, and the receiving holes 41 d. The gap 33, the chamber 12, the gap 43, the accommodation holes 41c and 42c, and the accommodation holes 41d and 42d are also pressurized to atmospheric pressure or higher.

  Next, the mold 2 is opened (the movable mold 4 is moved away from the fixed mold 3). At this time, since the cavity 11, the gap 33, the chamber 12, the gap 43, the accommodation holes 41c and 42c, and the accommodation holes 41d and 42d are previously pressurized to atmospheric pressure or higher, it is unnecessary for the actuator for opening the mold 2. There is no load.

Subsequently, an actuator (not shown) for moving the take-out member 6 is operated to move the take-out member 6 to the take-out position (position indicated by a two-dot chain line in FIG. 2), and the push-out pins 61a and 61b are moved to the cavity 11. Protrusively.
As a result, the tips of the extrusion pins 61 a and 61 b come into contact with the molded product attached to the cavity surface 41 b to extrude the molded product, and the molded product is peeled from the mold 2.
When the molded product take-out process 400 is completed, the process proceeds to the release material application process 100, and the next molded product is molded.
In the above-described embodiment, the form using compressed air for the operation of the exhaust valve and the form using the injection cylinder 53 and the hydraulic cylinder are used. However, the present invention is not limited to this, and other means that perform the same function are adopted. May be.

As described above, the die casting apparatus 1 is
A mold 2 composed of a fixed mold 3 and a movable mold 4 in which cavity surfaces 31b and 41b forming the outer shape of the cavity 11 are formed on the mating surfaces 31a and 41a, respectively.
The receiving holes 41c and 42c that penetrate from the cavity surface 41b to the back surface 42b of the movable mold 4 and the extrusion pins 61a and 61b that are slidably accommodated in the accommodation holes 41d and 42d, respectively, are the bases of the extrusion pins 61a and 61b. A movable plate 62 fixed to the movable plate 62, and sliding pins 63a and 63b fixed to the other surface of the movable plate 62, and a takeout member 6 for separating and taking out the molded product attached to the cavity surface 41b;
The movable plate 62 of the take-out member 6 is accommodated so as to be movable in the sliding direction of the push pins 61a and 61b, and the chamber 12 communicating with the accommodation holes 41c and 42c and the accommodation holes 41d and 42d faces the back surface 42b of the movable mold 4. A chamber forming member 7 that slidably supports the middle portions of the sliding pins 63a and 63b of the take-out member 6, and
A cavity pressurizing and depressurizing device 8 for pressurizing and depressurizing the cavity 11;
A chamber pressurizing and depressurizing device 9 for pressurizing and depressurizing the chamber 12;
It comprises.
This configuration has the following advantages.
In the die casting apparatus 1 of this embodiment, the chamber 12 is formed so as to be “externally attached” facing the back surface 42 b of the movable mold 4 of the mold 2. Therefore, the strength of the mold 2 is sufficiently ensured compared to the case where the chamber is formed inside the mold, and the deformation of the mold 2 due to the molten metal pressure when the molten metal is injected into the cavity 11 can be suppressed. It is.
As a result, air entrainment is prevented, dimensional accuracy is ensured, and generation of burrs is prevented, thereby contributing to improvement in the quality of the molded product. Further, the molded product can be easily taken out from the mold, and the workability is excellent.

The take-out member 6 of the die casting apparatus 1 is
The movable plate 62 includes substantially ring-shaped O-rings 64a and 64b that are in contact with the surface on which the sliding pins 63a and 63b are fixed and the inner wall surface of the chamber 12, and are fitted on the sliding pins 63a and 63b. Is.
With this configuration, the O-rings 64a and 64b do not rub against other members when the moving plate 62 moves, and damage can be prevented.
Therefore, it is not necessary to frequently maintain the O-rings 64a and 64b, and it is possible to reduce labor and cost for maintaining the equipment.

The fixed mold 3 of the die casting apparatus 1 includes a fixed-side insert 31 formed with a cavity surface 31b that forms the outer shape of the cavity 11, and a fixed-side main mold 32 that removably fixes the fixed-side insert 31. ,
The movable mold 4 of the die casting apparatus 1 includes a movable side insert 41 formed with a cavity surface 41b that forms the outer shape of the cavity 11, and a movable side main mold 42 that detachably fixes the movable side insert 41.
With this configuration, it is possible to reduce only the fixed side insert 31 and the movable side insert 41 that require high dimensional accuracy and may be damaged by contact with the molten metal, thereby reducing the equipment maintenance cost. is there.
Further, air is supplied to the cavity 11 from the gap between the nest and the main mold at the time of depressurization, and the vacuum degree of the cavity 11 at the time of depressurization is prevented from being reduced, thereby contributing to the improvement of the quality of the molded product.

In addition, the die casting method of this embodiment is
A mold 2 composed of a fixed mold 3 and a movable mold 4 in which cavity surfaces 31b and 41b forming the outer shape of the cavity 11 are formed on the mating surfaces 31a and 41a, respectively.
The receiving holes 41c and 42c that penetrate from the cavity surface 41b to the back surface 42b of the movable mold 4 and the extrusion pins 61a and 61b that are slidably accommodated in the accommodation holes 41d and 42d, respectively, are the bases of the extrusion pins 61a and 61b. A movable plate 62 fixed to the movable plate 62, and sliding pins 63a and 63b fixed to the other surface of the movable plate 62, and a takeout member 6 for separating and taking out the molded product attached to the cavity surface 41b;
The movable plate 62 of the take-out member 6 is accommodated so as to be movable in the sliding direction of the push pins 61a and 61b, and the chamber 12 communicating with the accommodation holes 41c and 42c and the accommodation holes 41d and 42d faces the back surface 42b of the movable mold 4. A chamber forming member 7 that slidably supports the middle portions of the sliding pins 63a and 63b of the take-out member 6, and
A cavity pressurizing and depressurizing device 8 for pressurizing and depressurizing the cavity 11;
A chamber pressurizing and depressurizing device 9 for pressurizing and depressurizing the chamber 12;
A die casting method using a die casting apparatus 1 comprising:
A depressurization step 200 for closing the mold 2 and depressurizing the cavity 11 and the chamber 12;
A molding process 300 for supplying molten metal to the cavity 11 and solidifying the molten metal to mold a molded product;
A molded product removal step 400 in which the cavity 11 and the chamber 12 are pressurized to atmospheric pressure or more to open the mold 2, the extrusion pins 61 a and 61 b protrude into the cavity 11, and the molded product is peeled off from the mold 2;
It comprises.
This configuration has the following advantages.
In the die casting apparatus 1 of this embodiment, the chamber 12 is formed so as to be “externally attached” facing the back surface 42 b of the movable mold 4 of the mold 2. Therefore, the strength of the mold 2 is sufficiently ensured compared to the case where the chamber is formed inside the mold, and the deformation of the mold 2 due to the molten metal pressure when the molten metal is injected into the cavity 11 can be suppressed. It is.
As a result, air entrainment is prevented, dimensional accuracy is ensured, and generation of burrs is prevented, thereby contributing to improvement in the quality of the molded product. Further, the molded product can be easily taken out from the mold, and the workability is excellent.

In addition, the die casting method of this embodiment is
Before the decompression step 200,
A release agent coating step 100 is provided for applying a release agent to the cavity surfaces 31b and 41b formed on the mating surfaces of the fixed mold 3 and the movable mold 4 in a state where the chamber 12 is pressurized to atmospheric pressure or higher.
By comprising in this way, it prevents that a molded product adheres firmly to cavity surface 31b * 41b, and makes it easy to take out a molded product.
In addition, it is possible to prevent the release agent from entering and remaining in the accommodation holes 41c and 42c, the accommodation holes 41c and 42c, the gap 33, and the gap 43. As a result, a reduction in the degree of vacuum at the time of decompression of the cavity 11 due to the remaining release agent is prevented, which contributes to an improvement in the quality of the molded product.

The figure which shows one Embodiment of the die-casting apparatus which concerns on this invention of a state with the metal mold | die closed. The figure which shows one Embodiment of the die-casting apparatus which concerns on this invention of a state with the open mold. The flowchart which shows one Embodiment of the die-casting method which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Die casting apparatus 2 Mold 3 Fixed mold 4 Movable type 6 Taking out member 7 Chamber forming member 8 Cavity pressure increasing / decreasing apparatus 9 Chamber pressure increasing / decreasing apparatus 11 Cavity 12 Chamber 31a / 41a Mating surface 31b / 41b Cavity surface 61a / 61b Plate 63a / 63b Slide pin

Claims (7)

A mold composed of a fixed mold and a movable mold in which a cavity surface forming the outer shape of the cavity is formed on the mating surface;
Extrusion pin slidably accommodated in an accommodation hole penetrating from the cavity surface to the back surface of one or both of the fixed mold and the movable mold, and a movable plate having a base portion of the extrusion pin fixed to one surface And a slide pin fixed to the other surface of the moving plate, and a takeout member for peeling off and taking out the molded product attached to the cavity surface;
A moving plate of the take-out member is accommodated so as to be movable in the sliding direction of the push pin, and a chamber communicating with the accommodation hole is formed facing the back surface of either the fixed mold or the movable mold. A chamber forming member that slidably supports a middle portion of the sliding pin of the takeout member;
A cavity pressure increasing / decreasing device for pressurizing and depressurizing the cavity;
A chamber pressurizing and depressurizing device for pressurizing and depressurizing the chamber;
A die casting apparatus comprising: The take-out member is
2. The die casting apparatus according to claim 1, further comprising a substantially ring-shaped sealing member that is in contact with a surface of the moving plate on which the sliding pin is fixed and an inner wall surface of the chamber and is fitted onto the sliding pin. . The fixed mold comprises a fixed-side insert in which a cavity surface that forms the outer shape of the cavity is formed, and a fixed-side main mold that removably fixes the fixed-side insert.
3. The movable mold according to claim 1, wherein the movable mold includes a movable nest having a cavity surface that forms an outer shape of the cavity, and a movable main mold that detachably fixes the movable nest. Die casting device. A mold composed of a fixed mold and a movable mold in which a cavity surface forming the outer shape of the cavity is formed on the mating surface;
Extrusion pin slidably accommodated in an accommodation hole penetrating from the cavity surface to the back surface of one or both of the fixed mold and the movable mold, and a movable plate having a base portion of the extrusion pin fixed to one surface And a slide pin fixed to the other surface of the moving plate, and a takeout member for peeling off and taking out the molded product attached to the cavity surface;
A moving plate of the take-out member is accommodated so as to be movable in the sliding direction of the push pin, and a chamber communicating with the accommodation hole is formed facing the back surface of either the fixed mold or the movable mold. A chamber forming member that slidably supports a middle portion of the sliding pin of the takeout member;
A cavity pressure increasing / decreasing device for pressurizing and depressurizing the cavity;
A chamber pressurizing and depressurizing device for pressurizing and depressurizing the chamber;
A die casting method using a die casting apparatus comprising:
A depressurizing step of closing the mold and depressurizing the cavity and the chamber;
A molding step of supplying a molten metal to the cavity and solidifying the molten metal to mold a molded product;
Pressurizing the cavity and the chamber above atmospheric pressure to open the mold, protruding the extrusion pin into the cavity, and removing the molded article from the mold;
A die casting method comprising: Before the decompression step,
5. The die casting according to claim 4, further comprising a release agent application step of applying a release agent to a cavity surface formed on a mating surface of the fixed mold and the movable mold in a state where the chamber is pressurized to an atmospheric pressure or higher. Method. The molded product takeout member is:
6. A substantially ring-shaped sealing member that abuts on a surface of the moving plate on which a sliding pin is fixed and an inner wall surface of the chamber and is fitted on the sliding pin. The die casting method described. The fixed mold comprises a fixed-side insert in which a cavity surface that forms the outer shape of the cavity is formed, and a fixed-side main mold that removably fixes the fixed-side insert.
7. The movable mold according to any one of claims 4 to 6, wherein the movable mold includes a movable nest having a cavity surface that forms an outer shape of the cavity, and a movable main mold for detachably fixing the movable nest. The die-casting method according to claim 1.

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